Ibanez TM-5 not working

[Bubesz]

Hello everyone!

A friend of mine have an Ibanez TM-5 pedal which stopped working some time ago and he asked me to have a look at it if I can fix it. Well, I can't, so I ask for your help He said he had a power supply (a 7.5 volt Casio, originally for a synth) and there was a shortage in it. After that the pedal broke down as well. I had a look at the TM-5 and swapped a fried diode going from ground to supply (a 1n4002, I only had a 1n4007 but never mind). There were no other visible signs of damage. When I tested it, the bypass worked but when the pedal was on, the signal was weak and much more distorted than it should be (it's strange but I know it shouldn't sound like this). There was also a kind of octave-down effect on the higher notes ( I also experience this with a pedal I built). I heard somewhere that it can be a faulty cap, but which?

What is your opinion?

I can measure some voltages if it helps.